Fluorescent and phosphorescent tube



Nov. 2, 1943. ABADIE 2,333,085

FLUORESCENT AND PHOSPHORESCENT TUBE Filed Jan. 22, 1940 IN VENTOR.

ATTORNEY$ Patented Nov. 2, 1943 2,333,085 FLUORESCENT AND PHOSPHORESCEN T TUBE Jean Baptiste Joseph Marcel Abadle,

Puteaux,

France; vested in the Alien Property Custodian Application January 22, 1940, Serial No. 315,015 3 Claims. (Cl. 176-122) This invention relates to electronic discharge tubes, and it is directed particularly to the employment of phosphorescent and fluorescent bodies in the tubes.

In the past it has been the common practice to apply photoluminescent, that is, phosphorescent and fluorescent materials to the interior surface of a luminescent tube, in the form of a thin film of coating. In general, sulphides, tungstates, silicates, etc., have been used for this purpose. However, it has been difficult to obtain uniform homogeneous distribution of the material forming the film, and manufacturing problems have been encountered in the application of the film to the wall of the tube. Moreover, only a fraction of the total light emitted from these substances is given off from the tube as useful lumination, when the phosphorescent and fluorescent bodies are employed in the film arrangement.

The objective of the present invention has been to overcome these defects and difliculties, and to produce tubes of greater luminating power, which are capable of being manufactured easily and economically.

Briefly, the present invention is predicated upon the concept of combining the phosphorescent or fluorescent substances with fabric material, and then inserting the fabric material into the tube, so as to obtain a photoluminescent glow from the substance in the fabric when the tube is operated.

The fabric containing the photoluminescent material is configurated either in the form of a mantle of cylindrical shape adapted to he slipped into the interior of the tube, or in the form of a disc or bafiie arranged for disposition within the tube, so that the fluorescent or phosphorescent material is excited by the electric discharge within the tube. Mantles may be generally similar to the Auer or Welsbach mantles with the exception, however, that they are employed in the electronic tube and that instead of being coated with thorium or cerium oxide they contain or carry mineral phosphorescent of fluorescent bodies.

Qther objects and further features of the invention are disclosed in the following specification and in the accompanying drawing in which:

Figure 1 illustrates a typical fabric material configurated in the form of a mrntle.

Figure 2 illustrates a mantle disposed within a tube.

Figure 3 shows a tube having a portion of its inner surface carrying phosphorescent or fluorescent fabric.

Figure 4 is a modification of the mantle arrangement shown in Figure 2.

Figure 5 shows the further modification of the arrangement of Figure 4.

Figure 6 shows the typical arrangement for using the phosphorescent or luminescent fabric in the form of baiiies.

Figure 7 likewise shows a baflle type of arrangement of the fabric material.

The mantle shown in Figure 1 is of cylindrical or tubular formation, the threads or meshes of the fabric forming the photoluminescent screen being indicated at 2. A mantle of this type is adapted readily for insertion within a tube 3, as indicated in Figure 2.

In Figure 3 a fabric screen 4, made of the fabric, containing or coated with the phosphorescent or fluorescent mineral, is shown. It is disposed over only a portion of the interior surface of a tube, for instance, one-half of the circumference of the Wall. By this arrangement all of the light from the tube will be emitted as useful lumination, and none of it will be intercepted as it would be were the tube lined with a film of the phosphorescent or fluorescent mineral.

The structure of Figure 4 embodies a pair of tubes 5 and 6, one carried concentrically within the other. The mantle I of the fabric containing the photoluminescent substance is carried over the interior tube 6. The interior part of the tube 6 may be silvered, and so be used as an electrode to ionize the gas as at 3, and to reflect the light emitted by the luminescent material.

It has been determined that the luminosity of the fluorescent and phosphorescent substance is not dependent upon the direct action of ultra violet light, but rather upon the electronic emission of the phosphorescent producing materials, or the heavy metals contained in them. Otherwise expressed, it has been discovered that when the electronic and ionic friction on the phosphorescent or fluorescent substances is increased, these substances become more luminous.

The structure of Figure 5 is particularly suited to the advantages of this determination. A mantle 8 is held longitudinally within a tube 9 by means of an arm extending inwardly from each end of the tube. The mantle is reenforced by longitudinal supports I 0, if necessary. These longitudinal supports preferably are made of refractory material. onic emission electrodes II and I2. These may The tube 9 contains thermi-' be made of alkaline earth, for instance, and operated to produce an are or discharge therebetween. The two sides of the fluorescent or phosphorescent mantle 8 are subjected to the direct action of the electronic friction provoked by the electric discharge, and the mantle, therefore, glows with increased luminosity.

In the structure of Figure 6. a central arm or support 13 is employed to carry a plurality of discs of the phosphorescent or luminescent fabrication in spaced relationship. The support containing the discs may be inserted directly in a tube so that the discs serve as baffles for receiving the electronic discharge within the tube. As shown in Figure 7, a series of ionic elements is employed so as to increase to a maximum the frictional surface of the fluorescent bodies subjected to the electronic discharge in a tube with out increasing the volume of the tube.

In making luminescent tubes according to the present invention the filling pressure of the gas or metallic vapors which may be employed is influenced by the openings in the mesh of the fabric. It is preferable that the filling pressure of the gas or metallic vapors in the tube be such that the free path left for the passage of electrons be greater than the space between the meshes of the phosphorescent or fluorescent fabric.

Having described my invention, I claim:

1. An electronic discharge device, comprising an envelope containing an ionizable gas, a pair of electron emissive electrodes disposed within the envelope in spaced relationship, and a plurality of membranes each containing a photoluminescent substance disposed within the tube transversely across the path of discharge of electrons between said electrodes, said membranes beingpermeable to ionic and electronic beams, the degree of permeability substantially influencing the total brilliancy of the device.

2. In an electric discharge device, a tubular envelope containing a rarefied gaseous atmosphere, electron emitting electrodes sealed in the ends of the envelope, a longitudinal support positioned in the enevelope between the electrodes, a plurality of electron permeable fabric discs carried by said support at longitudinally spaced intervals, said discs being composed of fabric material coated with luminescent material adapted to glow by irradiation when excited by cathode rays emanating from one of said electrodes, the porosity of the material of the discs being predetermined to control the degree of luminosity of the device consequent upon the passage of a discharge through the gaseous atmosphere in the envelope.

3. In an electric discharge device the combination comprising a container having a rarefied gaseous atmosphere therein, electrodes formin a cathode and an anode sealed in the container,.

means for producing an electron discharge between said electrodes, a plurality of discs supported in the path of said discharge at spaced intervals, said discs being composed of a fabric material impregnated with a photoluminescent substance, the porosity of said discs being sufiicient to make them permeable to the electron stream impinging thereagainst, whereby the photoluminescent substance is excited by the cathode rays and caused to emit light characteristic of the substance.

JEAN BAPTISTE JOSEPH MARCEL ABADIE. 

